1. Technical Field
The invention relates to network protocols and data packets. More particularly, the invention relates to the decoding of network protocols and processing of packet data during packet reception without the time-consuming overhead of software or software/hardware implementations. In addition, the invention allows one pass parsing of the data, eliminating the buffering of data packets for different stacks, and thus minimizing the memory usage.
2. Description of the Prior Art
Computer networks necessitate the provision of various communication protocols to transmit and receive data. Typically, a computer network comprises a system of devices such as computers, printers and other computer peripherals, communicatively connected together. Data are transferred between each of these devices through data packets which are communicated through the network using a communication protocol standard. Many different protocol standards are in current use today. Examples of popular protocols are Internet Protocol (IP), Internetwork Packet Exchange (IPX), Sequenced Packet Exchange (SPX), Transmission Control Protocol (TCP), and Point to Point Protocol (PPP). Each network device contains a combination of hardware and software that translates protocols and process data.
An example is a computer attached to a Local Area Network (LAN) system, wherein a network device uses hardware to handle the Link Layer protocol, and software to handle the Network, Transport, and Communication Protocols and information data handling. The network device normally implements the one Link Layer protocol in hardware, limiting the attached computer to only that particular LAN protocol. The higher protocols, e.g. Network, Transport, and Communication protocols, along with the Data handlers, are implemented as software programs which process the data once they are passed through the network device hardware into system memory. The advantage to this implementation is that it allows a general purpose device such as the computer to be used in many different network setups and support any arbitrary network application that may be needed. The result of this implementation, however, is that the system requires a high processor overhead, a large amount of system memory, complicated configuration setup on the part of the computer user to coordinate the different software protocol and data handlers communicating to the computer's Operating System (O.S.) and computer and network hardware.
This high overhead required in processing time is demonstrated in U.S. Pat. No. 5,485,460 issued to Schrier et al on Jan. 16, 1996, which teaches a method of operating multiple software protocol stacks implementing the same protocol on a device. This type of implementation is used in Disk Operating System (DOS) based machines running Microsoft Windows. During normal operation, once the hardware verifies the transport or link layer protocol, the resulting data packet is sent to a software layer which determines the packets frame format and strips any specific frame headers. The packet is then sent to different protocol stacks where it is evaluated for the specific protocol. However, the packet may be sent to several protocols stacks before it is accepted or rejected. The time lag created by software protocol stacks prevent audio and video transmissions to be processed in real-time; the data must be buffered before playback. It is evident that the amount of processing overhead required to process a protocol is very high and extremely cumbersome and lends itself to applications with a powerful Central Processing Unit (CPU) and a large amount of memory.
Consumer products that do not fit in the traditional models of a network device are entering the market. A few examples of these products are pagers, cellular phones, game machines, smart telephones, and televisions. Most of these products have small footprints, 8-bit controllers, limited memory or require a very limited form factor. Consumer products such as these are simplistic and require low cost and low power consumption. The previously mentioned protocol implementations require too much hardware and processor power to meet these requirements. The complexity of such implementations are difficult to incorporate into consumer products in a cost effective way. If network access can be simplified such that it may be easily manufactured on a low-cost, low-power, and small form-factor device, these products can access network services, such as the Internet.